The Batong Line of the Beijing Subway (Chinese: 八通线; pinyin: bātōng xiàn) is a surface level rapid transit rail line in eastern Beijing. It extends Line 1 further east from Sihui to the suburbs in Tongzhou District. The Batong Line derives its name by combining the first character of Bawangfen (八王坟), another place name for Sihui, and Tongzhou (通州) the eastern suburban district of Beijing which the line serves. The Batong Line is sometimes abbreviated as 8T but it should not be confused with Line 8 of the Beijing Subway.

The Batong Line is entirely above ground and runs 18.9 km from the Sihui Station in the west to Tuqiao in the east. Transfers are available to Line 1 at the Sihui and Sihui East stations. The colour of Batong Line that is shown on maps, like that of Line 1, is red.

The first east-bound train departs Sihui at 6:00am. The first west-bound train departs Tuqiao at 5:20am. The last east-bound train leaves Sihui 10:45pm. The last west-bound train leaves Tuqiao at 10:05pm. For the official timetable, see [2].

The Batong Line follows the Beijing-Tongzhou Expressway eastward from Sihui to Guanzhuang. Between Gaobeidian and Guanzhuang, the Batong Line and its stations are built into the highway's median. At Baliqiao, the Batong Line turns to the southeast and follows the Jingtang Road to Tuqiao, which is located just inside the Tuqiao Bridge exit on the eastern 6th Ring Road.

Construction of the Batong Line began on December 28, 2001 and the line opened on December 27, 2003.

In 2012, traffic on Batong Line was relieved by the opening of the parallel Line 6, with a 12.14% decrease in daily ridership and a 10-20% reduction in flow during rush hour.[5] However during peak hours sections the line still operates above 100% capacity.[5]

There will be platform doors on the Batong Line. There might be a south-eastern extension to Huanqiuyingcheng via Taiyuyuan, connecting the Yizhuang Line (future). The Batong Line might be combined with Line 1. There might be a Hugezhuang Line that starts from Batong Line's Tongzhoubeiyuan to Hugezhuang.